With the political conventions set for the next two weeks, now is the time to offer a summary of where Donald Trump and Hillary Clinton stand on tech's top issue, immigration.

Silicon Valley fears Trump, the presumptive Republican nominee for president. A letter released Thursday and signed by about 150 technologists, inventors and entrepreneurs, said Trump would be a disaster for innovation. Much of their criticism was directed at his proposed immigration policies.

Clinton, the presumptive Democratic nominee for president, is far more aligned with Silicon Valley on immigration.

The green card divide

Clinton supports near-automatic green cards for foreign students who earn an advanced STEM degree at a U.S. university. Although details of her plan have not been released, these "staple-a-green-card-to-the-diploma" proposals typically require the grad to first get a STEM job.

For his part, Trump wants a "pause" in issuing new green cards to foreign workers. The idea is to encourage employers to hire the unemployed. He argues this will also improve hiring of women and grow wages. The division between Trump and Clinton on employment-based green cards could not be sharper.

Trump has pitched a rewrite of the H-1B system. He wants to raises the wages of foreign workers and give preference to American workers. Clinton has yet to offer an H-1B reform plan.

But nothing is ever as clear as it seems. There are big uncertainties ahead.

Can Trump be trusted to reform the H-1B program?

No.

Gage Skidmore/Trump Campaign

Donald Trump at a rally in Florence, South Carolina, on Feb. 5, 2016

During the campaign Trump came very close to retreating on his promised H-1B reforms. In a GOP debate in Detroit, Trump said he was "changing" his H-1B positon after considering the arguments for keeping foreign students who graduate from U.S. universities in this country.

Trump is a businessman and a tough one. Jamaican model Alexia Palmer, who worked for Trump Model Management for just over three years, filed a lawsuit against that business in 2014. Palmer worked on an H-1B visa.

The lawsuit claimed that Palmer was to be paid $75,000 a year. But for all the work she did from 2011 to 2013, she received a check in the amount of $3,880. Palmer had signed a separate contract explicitly stating that she would be responsible for all expenses. The lawsuit alleged her employer "took more than 80%" of Palmer's "hard earned money by cloaking it as expenses."

The expenses included postage, "unnecessary cosmetic kits" and "expensive limousines, all at the plaintiff's expense," the lawsuit claimed. Supporting court records show a long list of expenses, including $4,000 in administrative fees, Federal Express charges, an Internet promo website and stylist charges, among others.

The case was dismissed in a New York federal court on a number of issues, including failure to first file an administrative complaint with the government. The case was never heard by a jury.

The Palmer case is just one labor dispute and doesn't definitely speak to what Trump would do as president. But he would be under enormous pressure to moderate his views to adopt more business-friendly reforms.

One of the voices Trump will be listening to is his vice presidential nominee, Mike Pence, the Indiana governor. As a congressman, Pence supported a 2006 bill to increase the 65,000 H-1B cap to 115,000. It included an escalator provision that would allow it to rise in respective years if demand exceeded the cap.

Is there reason to believe Trump will deliver H-1B reforms?

Yes.

Laid-off Disney IT workers have spoken at Trump rallies, and Trump has raised the visibility of displaced IT workers to a new level in a presidential campaign.

Trump's visa platform was drafted with the help of U.S. Sen. Jeff Sessions (R-Ala.), who was also the first U.S. senator to endorse him. His H-1B reforms are the same type of reforms being sought in a number of bills.

Sessions heads the Senate's immigration subcommittee, and is part of a group of bipartisan senators pushing for visa reforms. Sessions would likely keep a President Trump focused on reform.

Can Clinton be trusted to reform the H-1B program?

No.

Let's be clear: Clinton hasn't even suggested the idea of reforming the H-1B visa program.

Chris Usher/CBS

Former U.S. Secretary of State Hillary Clinton during the CBS News Democratic Presidential Debate at Drake University in Des Moines, Iowa, on Nov. 14, 2015.

Clinton doesn't mention the visa in her platform. It doesn't come up in the Democratic party's platform. Sen. Bernie Sanders (I-VT), who talked about the need for a H-1B visa reform in his campaign, didn't mention the issue in his recent endorsement of Clinton.

The only time that Clinton expressed any concern about IT workers was an interview this week with Vox. She said it was "heartbreaking" when IT workers must train their H-1B replacements.

But Clinton probably understands the importance of H-1B visa to India. While in Congress, Clinton co-founded and co-chaired the Senate India Caucus. She has had working ties with Tata Consultancy Services (TCS), one of the largest IT services firms in India, and that continued through her tenure as secretary of state. Ratan Tata, then chairman of Tata Group, a conglomerate whose holdings include TCS, was co-chair of the U.S.-India CEO Forum.

Clinton, similar to President Barack Obama, will accept H-1B reforms only as part of a comprehensive immigration reform proposal. That's a hard line. Some lawmakers, both Democratic and Republican, believe it is possible to get some H-1B reforms passed independent of a broader immigration reform package.

If Clinton, as president, couldn't get support for comprehensive immigration reform, would she be willing to seek H-1B reforms? Or would she hold any action on H-1B reforms hostage to comprehensive immigration reform?

Is there reason believe Clinton will deliver H-1B reforms?

Perhaps.

Clinton, in her Vox interview, made two key admissions about the H-1B visa program. She said the use of foreign replacements is a "cost-cutting measure to be able to pay people less than you would pay an American worker." Clinton also said that businesses find it easier to get a foreign worker because they will be "largely compliant."

That H-1B workers are hired because they are less expensive, and more reliant on or compliant with the employers who sponsor the visa, are two major criticisms of the program. And they are problems that could be addressed in standalone legislation.

As president, Clinton would be under pressure to take action on the H-1B program. Support for H-1B reform is bipartisan and appears to be growing. For instance, after Disney cut some 250 workers, Sen. Bill Nelson (D-Fla.), introduced an H-1B reform bill that was endorsed by Sen. Sessions.

Sen. Ted Cruz (R-Texas), once a supporter of a major H-1B cap increase, changed his view after he started campaigning for the GOP presidential nomination. With Sessions, he introduced an H-1B reform bill. Similarly, Sen. Richard Blumenthal (D-Conn.) revisited his support for a H-1B cap increase after hearing from laid-off Northeast Utilities IT workers. He has since moved into the reform camp.

The bipartisan support for H-1B reform in the Senate and House means, as president, Clinton would face ongoing pressure from allies in her own party to reform the program.